Apparatus, system and method of providing a conformable heater system

ABSTRACT

The disclosure is and includes at least an apparatus, system and method for a flexible heater sensor suitable for association with a fluid bag. The apparatus, system and method may include a conformable substrate on a ply of the fluid bag opposite a printed flexible heater; and a matched function ink set, printed onto at least one substantially planar face of the substrate. The matched function ink set forms: at least one conductive layer capable of receiving current flow from at least one power source; and at least one dielectric layer capable of at least partially insulating and at least partially limiting conductivity of the at least one conductive layer; wherein the matched ink set is matched to preclude detrimental interactions between the printed inks of each of the at least one conductive and dielectric layers, and to preclude detrimental interactions with the conformable substrate; and wherein the at least one conductive layer and the at least one dielectric layer comprise a sensing circuit that senses at least the temperature of fluid within the fluid bag.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.15/683,437, entitled APPARATUS, SYSTEM AND METHOD OF PROVIDING A FLUIDBAG HEATER, filed on Aug. 22, 2017 and U.S. application Ser. No.15/689,611, entitled APPARATUS, SYSTEM AND METHOD OF PROVIDING ACONFORMABLE HEATER IN WEARABLES, filed on Aug. 29, 2017, the entiretiesof which are incorporated herein by reference.

BACKGROUND Field of the Disclosure

The disclosure relates generally to printed electronics and, moreparticularly, to a conformable heater, such as for use in wearables.

Description of the Background

Printed electronics uses printing, or “additive,” methods to createelectrical (and other) devices on various substrates. Printing typicallydefines patterns on various substrate materials, such as using screenprinting, flexography, gravure, offset lithography, and inkjet.Electrically functional electronic or optical inks are deposited on thesubstrate using one or more of these printing techniques, thus creatingactive or passive devices, such as transistors, capacitors, resistorsand inductive coils.

Printed electronics may use inorganic or organic inks. These inkmaterials may be deposited by solution-based, vacuum-based, or otherprocesses. Ink layers may be applied one atop another. Printedelectronic features may include be or include semiconductors, metallicconductors, nanoparticles, nanotubes, etc.

Rigid substrates, such as glass and silicon, may be used to printelectronics. Poly(ethylene terephthalate)-foil (PET) is a commonsubstrate, in part due to its low cost and moderately high temperaturestability. Poly(ethylene naphthalate)- (PEN) and poly(imide)-foil (PI)are alternative substrates. Alternative substrates include paper andtextiles, although high surface roughness and high absorbency in suchsubstrates may present issues in printing electronics thereon. In short,it is typical that a suitable printed electronics substrate preferablyhas minimal roughness, suitable wettability, and low absorbency.

Printed electronics provide a low-cost, high-volume volume fabrication.The lower cost enables use in many applications but generally withdecreased performance over “conventional electronics.” Further, thefabrication methodologies onto various substrates allow for use ofelectronics in heretofore unknown ways, at least without substantialincreased costs. For example, printing on flexible substrates allowselectronics to be placed on curved surfaces, without the extraordinaryexpense that the use of conventional electronics in such a scenariowould require.

Moreover, conventional electronics typically have lower limits onfeature size. In contrast, higher resolution and smaller structures maybe provided using printed electronics, thus providing variability incircuit density, precision layering, and functionality not availableusing conventional electronics.

Control of thickness, holes, and material compatibility are essential inprinting electronics. In fact, the selection of the printing method(s)used may be determined by requirements related to the printed layers,layer characteristics, and the properties of the printed materials, suchas the aforementioned thicknesses, holes, and material types, as well asby the economic and technical considerations of a final, printedproduct.

Typically, sheet-based inkjet and screen printing are best forlow-volume, high-precision printed electronics. Gravure, offset andflexographic printing are more common for high-volume production. Offsetand flexographic printing are often used for both inorganic and organicconductors and dielectrics, while gravure printing is highly suitablefor quality-sensitive layers, such as within transistors, due to thehigh layer quality provided thereby.

Inkjets are very versatile, but generally offer a lower throughput andare better suited for low-viscosity, soluble materials due to possiblenozzle clogging. Screen printing is often used to produce patterned,thick layers from paste-like materials. Aerosol jet printing atomizesthe ink, and uses a gas flow to focus printed droplets into a tightlycollimated beam.

Evaporation printing combines high precision screen printing withmaterial vaporization. Materials are deposited through a high precisionstencil that is “registered” to the substrate. Other methods of printingmay be used, such as microcontact printing and lithography, such asnano-imprint lithography.

Electronic functionality and printability may counter-balance one other,mandating optimization to allow for best results. By way of example, ahigher molecular weight in polymers enhances conductivity, butdiminishes solubility. Further, viscosity, surface tension and solidscontent must be tightly selected and controlled in printing. Cross-layerinteractions, as well as post-deposition procedures and layers, alsoaffect the characteristics of the final product.

Printed electronics may provide patterns having features ranging from3-10 μm or less in width, and layer thicknesses from tens of nanometersto more than 10 μm or more. Once printing and patterning is complete,post treatment of the substrate may be needed to attain final electricaland mechanical properties. Post-treatment may be driven more by thespecific ink and substrate combination.

Typical heaters for use in wearables, such as in garments oraccessories, are manufactured using conventional electronics techniquesand manual labor. For example, rigid, thick, and bulky heaters aretypically provided, such as in association with printed circuit boardsand the like. The wiring that allows for operation of these thick, bulkyheaters is typically sewn into the wearables, such as between fabriclayers, to enclose the heating elements into the fabrics.

Moreover, less bulky heaters that are fabricated using atypical types ofprocessing are typically expensive, in part because of the complexfabrication steps needed to create such heaters. Hence, these heatersare not applicable for wearable applications. Further, either of theforegoing atypical or conventional types of heaters necessitates anextraordinary level of encapsulation if the wearable associated with theheater is, for example, to be laundered. This is particularly the caseif the wearable is to be laundered many times over its life cycle. Thatis, the limiting factor in the life cycle of the wearable should not bethe heater provided in association with the wearable.

Additionally and in an exemplary circumstance, medical bags, such asmedical fluid or blood bags, often require heating. Typically in theknown art, such heating is provided by an electronic heating hardwareunit into which the medical bag must be placed. Accordingly, relativelylarge and/or substantially immobile equipment constitutes the manner inwhich heat is provided to medical fluid bags in known embodiments.

Less bulky heaters that are fabricated using atypical types ofprocessing may provide enhanced mobility, but are typically veryexpensive, in part because of the complex fabrication steps needed tocreate such heaters, and are generally not highly reliable. Hence, theseheaters are not presently applicable for use in heating in wearables ormedical bags.

Therefore, less bulky heaters that may be assembled using in-line and/orhigh throughput processes, such as additive printing processes, andwhich is thus less complex in its fabrication resulting in morecost-efficient manufacturing, longer use life of the heater and thewearable, and other distinct advantages, is needed. Such a heater shouldbe formed in a thin, less bulky, more conformable and flexible format,and on a moldable substrate, to not only address the foregoing concerns,but also to allow for integration into more diverse types of uses.

Further, presently the characteristics, such as temperature, of a fluidbag, such as a medical fluid bag, are typically monitored using off bagcomponents, such as including a thermocouple to the bag or an infraredgun, by way of nonlimiting example. Such methods, however, mayfrequently subject the bag to improper temperature measurements becauseof, for example, human error, environmental or electrical interferencebetween the bag and the temperature reader, component failure due to theneed for various additional normal components to make the electricalconnection from the bag to the reader, and so on.

Additionally, present methods of indicating the level of fluid in a bag,such as a medical fluid bag, are limited to weight measurements, such aswherein a bag placed on an IV stand pulls down on a hook that iselectrically associated with a measurement scale. Such methods ofmeasuring a level of fluid remaining in the bag are highly inaccurate,however, at least because of the possibility of human error, such assomeone pulling down on the bag, environmental and/or use factors, suchas shaking of the scale hook when the IV stand is moved, the breaking ofelectrical connections when an IV stand is moved, and so on.

Yet further, in part due to the inaccuracy of temperature and levelsensing presently available in conjunction with fluid bags, methods ofconveying temperature and fluid level data to one or more interestedparties are presently wholly inadequate. For example, the reading on aninfrared gun may be inaccurate for the reasons stated above, such ashuman error wherein equipment or body parts come between the IR gun andthe bag. Further, the readout of a scale and attempt to sense fluidlevel in a bag may require conversion by a human user, or may beinaccurate for all of the foregoing reasons and additionally because oflack of accounting for the weight of the bag itself, by way of example.

Therefore, the need exists not only for improved designs and printingmethods to place a heater in association with a fluid bag, such as amedical fluid bag, but additionally for improved methodologies ofassociating bag characteristic measurements, such as temperaturemeasurement and level sensing, with a fluid bag, and additionally ofproviding the data logged in association with such temperature sensingand level sensing to one or more interested users.

SUMMARY

Thus, the disclosure provides at least an apparatus, system and methodfor a flexible heater. The flexible heater comprises a conformablesubstrate; a matched function ink set, printed onto at least onesubstantially planar face of the substrate to form at least a conductivelayer capable of receiving current flow from at least one power source;a resistive layer electrically associated with the at least oneconductive layer and comprising a plurality of heating elements capableof generating heat upon receipt of the current flow; and a dielectriclayer capable of at least partially insulating the at least oneresistive layer, wherein the matched ink set is matched to precludedetrimental interactions between the printed inks of each of the atleast one conductive, resistive and dielectric layers, and to precludedetrimental interactions with the conformable substrate.

The flexible heater may additionally include an encapsulation that atleast partially seals at least the conformable substrate having thematched function ink set thereon from environmental factors. Theflexible heater may additionally be integrated into the wearable of theconformable substrate having the matched ink set thereon.

The flexible heater may further comprise a driver circuit connectivelyassociated with the at least one conductive layer. The driver circuitmay comprise a control system, and wherein an amount of heat deliveredby the heating elements is controlled by the control system.

The disclosure also is and includes at least an apparatus, system andmethod for a flexible heater sensor suitable for association with afluid bag. The apparatus, system and method may include a conformablesubstrate on a ply of the fluid bag opposite a printed flexible heater;and a matched function ink set, printed onto at least one substantiallyplanar face of the substrate. The matched function ink set forms: atleast one conductive layer capable of receiving current flow from atleast one power source; and at least one dielectric layer capable of atleast partially insulating and at least partially limiting conductivityof the at least one conductive layer; wherein the matched ink set ismatched to preclude detrimental interactions between the printed inks ofeach of the at least one conductive and dielectric layers, and topreclude detrimental interactions with the conformable substrate; andwherein the at least one conductive layer and the at least onedielectric layer comprise a sensing circuit that senses at least thetemperature of fluid within the fluid bag.

Thus, the disclosure provides improved designs and printing methods toplace a heater in association with a fluid bag, such as a medical fluidbag, wearables, and additionally for improved methodologies ofassociating bag characteristic measurements, such as temperaturemeasurement and level sensing, with a fluid bag, and additionally ofproviding the data logged in association with such temperature sensingand level sensing to one or more interested users.

BRIEF DESCRIPTION OF THE DRAWINGS

The exemplary compositions, systems, and methods shall be describedhereinafter with reference to the attached drawings, which are given asnon-limiting examples only, in which:

FIG. 1 is a schematic and block diagram illustrating a heater accordingto the embodiments;

FIG. 2 is a schematic and block diagram illustrating a heater accordingto the embodiments;

FIG. 3 is an exemplary implementation of the embodiments having aconductor layer with contact points at the top right and bottom left ofthe heating system;

FIG. 4 is an exemplary implementation of a conductive and resistivelayer heating system;

FIG. 5 is an exemplary implementation of an embodiment having anenhanced size of the conductive layer associated with the contact padsat the top of the device;

FIG. 6 illustrates an exemplary implementation of a heating systemenclosed in an encapsulation layer;

FIG. 7 illustrates an exemplary implementation in which the heatingsystem is laminated to a textile;

FIG. 8 is a flow diagram illustrating an exemplary method of providing aconformable heater, such as for use in a wearable;

FIG. 9 is a flow diagram illustrating a method of using a conformableheater system within a wearable;

FIG. 10 is an illustration of an exemplary sensing circuit;

FIGS. 11A-11D are illustrations of exemplary heating circuits;

FIG. 12 is an illustration of an exemplary sensing circuit;

FIGS. 13A-13B are illustrations of exemplary sensing circuits;

FIGS. 14A-14C are illustrations of exemplary mobile apps for sensordata;

FIG. 15 is an illustration of an exemplary sensing circuit;

FIG. 16 is an illustration of an exemplary sensing circuit; and

FIGS. 17A-17C are illustrations of exemplary sensing circuits.

DETAILED DESCRIPTION

The figures and descriptions provided herein may have been simplified toillustrate aspects that are relevant for a clear understanding of theherein described apparatuses, systems, and methods, while eliminating,for the purpose of clarity, other aspects that may be found in typicalsimilar devices, systems, and methods. Those of ordinary skill may thusrecognize that other elements and/or operations may be desirable and/ornecessary to implement the devices, systems, and methods describedherein. But because such elements and operations are known in the art,and because they do not facilitate a better understanding of the presentdisclosure, for the sake of brevity a discussion of such elements andoperations may not be provided herein. However, the present disclosureis deemed to nevertheless include all such elements, variations, andmodifications to the described aspects that would be known to those ofordinary skill in the art.

Embodiments are provided throughout so that this disclosure issufficiently thorough and fully conveys the scope of the disclosedembodiments to those who are skilled in the art. Numerous specificdetails are set forth, such as examples of specific components, devices,and methods, to provide a thorough understanding of embodiments of thepresent disclosure. Nevertheless, it will be apparent to those skilledin the art that certain specific disclosed details need not be employed,and that embodiments may be embodied in different forms. As such, theembodiments should not be construed to limit the scope of thedisclosure. As referenced above, in some embodiments, well-knownprocesses, well-known device structures, and well-known technologies maynot be described in detail.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. For example, asused herein, the singular forms “a”, “an” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The steps, processes, and operations described herein are notto be construed as necessarily requiring their respective performance inthe particular order discussed or illustrated, unless specificallyidentified as a preferred or required order of performance. It is alsoto be understood that additional or alternative steps may be employed,in place of or in conjunction with the disclosed aspects.

When an element or layer is referred to as being “on”, “upon”,“connected to” or “coupled to” another element or layer, it may bedirectly on, upon, connected or coupled to the other element or layer,or intervening elements or layers may be present, unless clearlyindicated otherwise. In contrast, when an element or layer is referredto as being “directly on,” “directly upon”, “directly connected to” or“directly coupled to” another element or layer, there may be nointervening elements or layers present. Other words used to describe therelationship between elements should be interpreted in a like fashion(e.g., “between” versus “directly between,” “adjacent” versus “directlyadjacent,” etc.). Further, as used herein the term “and/or” includes anyand all combinations of one or more of the associated listed items.

Yet further, although the terms first, second, third, etc. may be usedherein to describe various elements, components, regions, layers and/orsections, these elements, components, regions, layers and/or sectionsshould not be limited by these terms. These terms may be only used todistinguish one element, component, region, layer or section fromanother element, component, region, layer or section. Terms such as“first,” “second,” and other numerical terms when used herein do notimply a sequence or order unless clearly indicated by the context. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of the embodiments.

Historically and as discussed throughout, the formation of many smallaspects of devices or small devices has generally integrated theprocesses of deposition and etching. That is, traces, such as conductivetraces, dielectric traces, insulating traces, and the like, whichinclude formation of device features such as wave guides, vias,connectors, and the like, have generally been formed by subtractiveprocesses, i.e., by creating layers which were later etched to removeportions of those layers to form the desired topologies and features ofa device.

Additive printing processes have been developed whereby device featuresand aspects are additively formed, i.e., are formed by “printing” thedesired feature at the desired location and in the desired shape. Thishas allowed for many devices and elements of devices that werepreviously formed using subtractive processes to be formed via additiveprocesses, including, but not limited to, printed transistors,carbon-resistive heating elements, piezo-elements and audio elements,photodetectors and emitters, and devices for medical use, such asglucose strips and ECG straps.

In short, the printing of such devices is dependent on a number offactors, including matching deposited materials, such as inks, tosubstrates for particular applications. This ability to use a variety ofsubstrates may afford unique properties to printed devices that waspreviously unknown in etched devices, such as the ability for devices tostretch and bend, and to be used in previously unknown or inhospitableenvironments, such as use as conformable heaters in wearables that areto be laundered. By way of non-limiting example, the ability to printelectronic traces on plasticized substrates allows for those substratesto be conformed after printing has occurred.

However, known additive properties do present limitations over theproperties previously available using subtractive processing. Forexample, it is typical that conductive traces formed using additiveprocesses have more limited conductivity than the conductive tracespreviously formed using subtractive processes. This is, in part, becausepure copper traces provided using subtractive processes are presentlyunavailable to be printed using modern additive processing. Accordingly,some devices and elements thereof, such as heaters, may be subjected tosubstantial modification in order to accommodate the modified propertiesavailable using printed traces in additive processes, as compared to theuse of conventional electronics-formation techniques.

In the embodiments, a large number of factors must be balanced in eachunique application in order to best arrive at properties that mostclosely approximate those properties previously available only insubtractive processes. For example, in the disclosed devices andprocesses for creating those devices, compatibility must be assessed asbetween a substrate for printing and the receptivity of such substrate,the inks employed and the conductivity thereof, the fineness of theprinted traces used, the pitch, density and consistency of the printedinks, the type of printing performed, i.e., screen printing versus othertypes of printing, the thickness of the printed layers, and the like.Moreover, because multiple inks may be employed in order to create thedisclosed heating elements, the compatibility of the inks used with oneanother is also an aspect of the embodiments. For example, chemicalreactions between inks, different curing methodologies between inks, andthe manner of deposition as between inks must all be assessed for allinks within a given ink set. Also of note, the skilled artisan willappreciate, in light of the discussion herein, that different inkswithin an ink set may have variable characteristics even afterdeposition. For example, certain inks may suffer from a valley effect inthe center of a deposited trace of that ink, while peaks are created atthe outer part of traces using that ink. Accordingly, because thethickness of a trace deposited using such an ink may allow foralleviation or heightening of the foregoing effect, the manner andconsistency of application of each ink within an ink set is noteworthyin the embodiments.

In the known art of incorporated heaters, printed circuit boards neededto be mechanically integrated, and hence accounted for, within eachproduct. However, the ability to use printed electronics with flexiblesubstrates and substrates having uneven topologies may allow for printedelectronics to be integrated as part of a product, instead ofnecessitating a mechanical integration of the electronics into thefinished product. Needless to say, this may include the use of printedelectronics onto substrates unsuitable for accepting electronics createdusing subtractive processes, such as fabrics, plastics that do notprovide “sticky” surfaces, organic substrates, and the like. This mayoccur, for example, because additive processes allow for differentprinting types within each subsequently printed layer of the printeddevice, and thereby the functionality provided by each layer, such asmechanical, electrical, structural, or other functionality, may bevaried as between printed layers throughout a deposition process.

Various solutions to balance the foregoing factors may be provided usingadditive processing. For example, a flexible substrate may be provided,wherein printing occurs on one or both sides of the substrate, such ason one or both sides of a medical bag. Thereby, traces may be producedon one or both sides of the bag to form one heater unit, or series orparallel heaters. In such instances, one or more vias may be createdbetween the sides of the bag, thus producing one heating system, ormultiple heat systems on opposing sides of the bag may be connectiblethrough or around the contents of the bag.

The embodiments provide at least a printed heater on a fluid bagsubstrate, such as a medical grade substrate as may be used for IVfluids, blood bags, or the like, or on a flexible substrate for use inassociation with a wearable, that is formed of a layer or layers offunctional ink(s), such as conductive inks, resistive inks, andinsulating inks, formed into traces using additive processes to therebyeffectuate the heater unit. Additional printed electronics may also beprovided using the same or similar additive processes, such aselectronics including sensors, antennas, such as RF, NFC, or the likeantennas, thermometers, thermocouples, fluid sensors, and the like.

The embodiments may accordingly provide not only heaters for heating,such as of wearable or of fluid within a bag, but additionally sensorsintegrated with the bag, such as to allow for traceability, networkconnectivity, and patient care reporting. This traceability,connectivity, and reporting may be manual or automatic, and may beoccasional, periodic, semi-continuous, and/or continuous in accordancewith the embodiments. These functionalities may allow for reductions inhuman error in patient monitoring and reporting, for example.

In accordance with the foregoing, the embodiments provide less bulkyheating equipment, such as to allow for optimized conditions in crampedspaces, such as in clothing, or in operating rooms or ambulances.Further, the embodiments provide improved patient care by regulating theheating of medical fluids to ensure the fluids do not under- or overheatand cause patient discomfort, injury, or death. Further, such heatersmay provide improved user comfort and ease of use.

Medical bags provide unique impediments to allowing for the use ofadditive processes, such as the printing of electronics, in associationtherewith. For example, because a medical bag typically has a textureassociated therewith, and is highly resistant to tearing and puncture,and hence is thick and highly flexible in association with thetexturing, a medical bag provides a unique substrate for additiveprocesses. Further, a medical bag must be inert in its properties inorder to allow for maintenance of sanitary conditions in associationwith patient care. The disclosed embodiments may be used in associationwith any such fluid bag, or with any other bag or substrate having suchimpediments to printing thereon, such as a flexible substrate forinclusion in a wearable. Furthermore, the disclosed embodiments may beused with any substrate of any size or shape.

More particularly, in the embodiments, a flexible heater for use in awearable or on a fluid bag may be printed onto a flexible andconformable organic or inorganic substrate, such as using a “matchedfunction” ink set. The flexible heater may be comprised of multiplelayers of inks or substances forming the matched function set. Forexample, and as illustrated with respect to the heater 10 of FIG. 1, aconductive layer 12 may be printed onto substrate 14 to allow forcurrent flow 16 to the heater. A resistive layer 18 may also orsubsequently be printed to allow for the heating effect 20 to occur uponheating of the resistors due to the current flow 16 therethrough.Further, a dielectric layer 22 may be printed to insulate the resistiveelements 18 a, both from shorting onto one another because of theconformable, flexible nature of the substrate 14, and to insulate theheat produced by the heating elements 18 a to avoid localizedoverheating.

Of course, the third layer 22 may additionally be provided below orbetween other layers 12, 18. For example, in a particular exemplaryembodiment, a printed heater not including a dielectric layer 106 may belimited in operation to a temperature range of 45 to 50 degrees Celsius;but the same heater including a dielectric layer 22 may be operated in atemperature range of 45 to 65 degrees Celsius without concern that theexcessive heat will pass improperly from the heater out into contactwith the environment, such as a hand placed on or near a fluid bag 50.

The substrate 14 onto which the layers 12, 18, 22 are printed mayinclude both organic and inorganic substrates, subject to the limitationthat substrates may be flexible and/or conformable to the wearable orfluid bag into or onto which the heater 10 is placed. Suitablesubstrates may include, but are not limited to PET, PC, TPU, nylon,glass, fabric, PEN, and ceramics.

As referenced above, various inks and ink sets may be used to form thelayers 12, 18, 22, or aspects thereof, in heater 10, and inks within theset may be matched to one another so as to avoid undesired chemicalinteractions during deposition, curing, etc., and/or may be matched tothe substrate onto which the inks are to be printed. By way ofnon-limiting example, conductive and resistive inks used may includesilver, carbon, PEDOT:PSS, CNT, or a variety of other printable,conductive, dielectric and/or resistive materials that will be apparentto the skilled artisan in light of the discussion herein.

In certain embodiments, particularly those exposed to the elementsand/or intended for laundering, or for use in harsh or sterile operatingroom conditions, the heating system 10 may preferably be encapsulated inorder to increase durability. In such cases, isolation fromenvironmental conditions 30, such as wet conditions, including rain,snow, or humidity, and/or insulation from wash and dry cycles and/orgeneral robust handling, may be performed. In such cases, anencapsulation system 32, such as a laminated pouch, may be optionallyprovided to enclose the heating system 10, and, in such cases, theencapsulation 32 may include connectivity and/or pass-throughs to allowfor the provision of power 40 through the encapsulation system 32 to theheating system 10. Finally, the heating system 10, such as including theencapsulation 32, may be integrated into a wearable or bag 50 via anyknown method, such as by sewing, lamination, or the like.

Thus, encapsulation 32 may provide waterproofing, airproofing, or thelike in order to protect the heating system and associated systems fromany adverse environmental factors 30. To provide the encapsulation 32,various known techniques may be employed. For example, acrylics may belaminated onto each side of the heater substrate 14, such as to create asealed lamination lip around the substrate 14, with the only projectionsextending therefrom having the acrylic lamination seal therearound.Further, such a laminated pouch may be treated with, for example,ultra-violet radiation such that the lamination is sealed onto, andprovides maximum protection of, the heating system 10. Of note however,the more layers that are added to the heating system, such as includingencapsulation 32, the less conformable to the wearable the heatingsystem will become, particularly in the case where added layers havesignificant thickness thereto.

In some embodiments, the encapsulation 32 that protects fromenvironmental conditions 30 may not require any secondary effort beyondproduction of the heating system 10. For example, substrate and inkcombinations may be selected that are submersible and conformable, oronly that portion of the substrate having printed electronics thereon toprovide the heating system may be sealed, such as with a single acryliclaminate, from environmental conditions.

As referenced above, heating systems 10 with or without encapsulation 32connect to one or more driving circuits 52. In certain embodiments,interconnection 54 to, for example, driver circuit 52 and/or power 40,may include a high contact surface area, such as to enable the heatingsystem 10 to draw significant current 16 from the power source 40. Alsoas referenced above, interconnection 54 may also include or compriseprinted electronic surfaces. Such interconnections 54 may additionallyinclude classical wiring, micro-connection, and/or electromechanicalconnection techniques, by way of non-limiting example.

The various interconnections 54, such including those from the drivercircuit 52 to external control systems, if any, and/or to the powersupply 56, may extend outwardly from the heating system 10. Theseinterconnections 54, as well as data requirements and powerrequirements, may be dependent on the unique structure of a givenheating system 10. For example, different carbon inks applied in theformulation of the heating system 10 may have different powerrequirements, such as 5-15 volts, or more particularly 5, 9, or 12volts, by way of non-limiting example.

Similarly, interconnects 54 may also be or include one or more universalconnectors known in the art for connectivity to, for example, theaforementioned voltages. Further, such a universal connector may be orinclude other known connector types, such as USB, micro-USB, mini-USB,lightning connector, and other known interconnects. Additionally andalternatively, proprietary interconnects 54 may be provided inconjunction with the embodiments.

The aforementioned driving circuit 52 may or may not be in directphysical association with the heating system 10 and the interconnects54. By way of example, the driver circuit 52 may be included as aself-contained system in the electrical pathway between the power source40 and the heating system 10. The driver circuit 52 may include controlsystems 52 a or connectivity to control systems 52 b, such as to allowfor remote and/or wireless control of the heating system 10, and/or toprovide limitations on the heating system, such as amount of heatdelivered, amount of current delivered or power drawn, variation betweendifferent heat delivery levels, and the like. Such remote connectivitymay include wireless connectivity, such as using NFC, blue tooth, WiFi,or cellular connectivity, such as to link to an app 60 on a user'smobile device 62, by way of non-limiting example.

Of note, the control system(s) 52 a, b, such as a Bluetooth-basedcontrol system, may allow for a change in temperature automatically ormanually, as referenced herein. Accordingly, the control system(s) 52 a,b may communicate, such as via Bluetooth, radio-frequency (RF),near-field communications (NFC), or the like, with a secondarycontrolling device, such as an app on a mobile device or an app orapplication on a medical monitoring system.

The aforementioned change may occur only for a certain period of time,which may be brief, such as particularly if the control system indicatesthat significant power will be consumed on a desired setting. Forexample, it may be manually or automatically selected that a user haspre-set a heater to heat to 85 degrees for 90 seconds, such as onlywhile the user briefly walks a dog outside in 10 degree weather, becauseit is understood that the user can recharge the system completelyimmediately after the short-term use. However, if a user is going on aone hour jog, and that jog is in the same 10 degree weather, the usermay prefer that the heater operate at 45 degrees for 50 minutes of thehour before the charge is fully consumed.

The power source 40 that delivers power to the heating system 10, suchas through the driver circuit 52, may be battery-driven, as mentionedabove, if local utility power is not available. The power source in suchinstances may preferably provide a battery life of, for example, 2-10hours, or, more specifically, 4-8 hours. This power may be provided, forexample, from a permanent power delivery system embedded in a garment oron a bag or IV-fluid pole, such as may use a rechargeable, removable,replaceable, or permanent battery, by way of non-limiting example, or bya secondary power source suitable to be plugged into the driver circuitsystem, such as may be embedded in or associated with utility-providedpower, medical equipment, a mobile device or other mobile power source,via a proprietary or non-proprietary connector, such as via a micro USB,lightning connector, or the like. As referenced, typical power provisionelements may include batteries, such as rechargeable batteries, such aslithium ion batteries. Such batteries may typically provide high levelsof heating very quickly, and then allow for a quick ramp-down in heatdelivery to avoid unnecessary power use during the ramp-up or ramp-downphases of power provision.

Atypical power sources may additionally be used to provide the powersource 40 for heating system 10. For example, kinetic power sources,such as those that store power based on movement, and/or other similarmagnetic and/or piezo-electric power systems, may be embedded in orconnectable to the wearable in order to provide primary, secondary,permanent, or temporary power to the heating system 10 via the drivercircuit 52. Likewise, primary, secondary, and/or atypical powersource(s) 40 may work together and in conjunction with theaforementioned system control, such as may be embedded in orcommunicatively associated with the driver circuit 52, to deliver poweronly upon particular triggers. For example, a wearable equipped withheaters at multiple locations, such as in the elbow of a sweatshirt andin the upper back region, may allow individual ones of those locationsto be activated only upon certain events indicated by on-board, such asprinted electronic, sensors 70, which may additionally be associatedwith the substrate 12. For example, a kinetic sensor may sense movement,and during the movement phase may activate a heater in a given location,such as in the upper back region in the prior example. However, uponsensing by the kinetic sensor of the stoppage of movement, the heatingelement in the elbow of the sweatshirt may be activated. This may bedone for any of a variety of reasons understood to the skilled artisan,such as for a pitcher who stops pitching between innings, but wishes tokeep his or her elbow “warm” so as to avoid injury.

Such variations in heating elements may not only occur for wearableshaving multiple heaters, but may similarly include variable heaterdesigns for different purposes. For example, smaller heaters consumeappreciably less power than larger heaters, and thus necessitate a lowerlevel power supply. Consequently, in the prior example of a sweatshirtfor a pitcher, a small heater located only proximate to the pitcher's“Tommy John” ligament in his or her elbow may require little power foractivation, but may nevertheless be enabled to deliver significanthealth impact to the wearer, such as to keep this oft-injured ligamentwarm after inactivity of more than 10 minutes has occurred.

Moreover, variability in heat levels, such as may be indicated by thedriver circuit system, may be made manually by the user or automaticallybased on system characteristics. For example, lower levels of heat in ahand warmer heating system, such as may be embedded in the pockets of asweatshirt or in a user's gloves, may be needed if the temperature iscolder, i.e., only a particular temperature differential fromenvironmental conditions may be necessary in order to make a user feel“warm”. That is, a user in an environment where the temperature is 10degrees Fahrenheit may feel much warmer if the user's gloves are warmedto 40 degrees Fahrenheit, rather than warming the gloves all the way toa maximum heating level of 65 degrees. However, in the event the ambienttemperature is 35 degrees, the user may need the heating element to goto 65 degrees in order for the user to feel the same level of “warmth”.

Additional considerations in power delivered to the heater and/or in theheat delivered may occur based on the use case of the wearable and ofthe heater. For example, in instances in which the heater might be insubstantially direct contact with or very close to the user's skin, thecontrol system associated with the driver circuit 52 discussed hereinmust limit the power such that the heating is not sufficient to burn,cause discomfort to, or otherwise harm the user. Such concerns may beaddressed, in part, through the use of self-regulating inks to providethe heating elements in certain exemplary embodiments.

For example, a positive temperature coefficient (PTC) heater may providea self-regulating heater. A self-regulating heater stabilizes at aspecific temperature as current runs through the heater. That is, astemperature is increased the resistance of the self-regulating heateralso increases, which causes reduced current flow and, accordingly, aninability of the heater to continue increasing in temperature. On thecontrary, if the temperature is reduced, the resistance decreases,thereby allowing more current to pass through the device. In a typicalembodiment, a self-regulating/PTC heater thus provides a stabilizedtemperature that is independent of the voltage applied to the heater.

Secondary systems 202 may be provided in conjunction with heating system10, such as to hold in warmth, as illustrated in FIG. 2. For example, inan embodiment having a laterally crossing pocket 204 in a sweatshirt,the single pocket across the sweatshirt may be lined 202 on the interiorportion thereof, and may have the heating element provided interior tothe lining of the pocket thereof, in order that the heat generated fromthe heating system 10 is held within the pocket 204 of the sweatshirt tothe maximum extent possible.

As discussed throughout, it may be advantageous, particularly forcertain types of wearables or fluid bags, that the heating system and/orthe other systems associated therewith be conformable. Thisconformability may apply to the application of forces by the user orbased on the activity, conformance to the physical profile of thewearable/bag itself, or the like. Additional considerations may arisedue to the conformability of the heating system and/or its associatedsystems. For example, delivered heat levels may vary based on thephysical configuration of the heating elements, i.e., when the heatingsystem is bent or partially folded, it may deliver greater or lesserheat in certain spots than is anticipated. Needless to say, some of thisvariability may be accounted for using a protective dielectric layer 22,such as is referenced above.

As discussed throughout, additional sensors, integrated circuits,memory, and the like may also be associated with the discussed heatingsystem 10, may be printed on the substrate 14 thereof, and/or may beformed on or in systems associated therewith, and/or on the substratesthereof. It goes without saying that, in such embodiments, theassociated electronics may be discrete from the heating system and thosesystems associated with the heating system, but may nevertheless besimilarly conformable to the wearable, the substrate of the heatingsystem, and so on. Further, those skilled in the art will appreciatethat such other electronic circuits may or may not be formed by printingprocesses on the same substrate, or on a physically adjacent substrate,of the heating system.

Moreover, the embodiments may include additional layers (not shown) tothose discussed above. For example, a heater substrate may be providedin the form of a highly adhesive sticker, wherein the sticker may or maynot provide a substrate suitable for receiving printed electronics onone side of the “sticker.” In such an instance, the compatibly adhesivesurface may be applied to the opposing face of the sticker, such as viaadditive process printing, lamination, deposition, or the like.

Of note, in order to associate the printed electronic layers with asubstrate throughout this disclosure, ink sets may be selected in lightof process parameters to form the heater and the operation environmentin which the bag will be used. For example, not only is application andcuring of each ink important in light of the function to be imparted tothe bag, but additionally the effects of operating conditions on eachink must be considered. In short, material compatibility must bemaintained, and a chemical inertness must be present between theadditive process elements. By way of nonlimiting example, the inksolvents used in relation to the inkset may be necessarily inert withrespect to both an IV bag, and the sanitary nature and operatingenvironment of the bag. Further, sterilization of the bag usingradioactive or ultraviolet processes, if needed, should not degrade theprinted electronic materials in the inkset or the functionality providedthereby. Yet further, the surface energy of the substrate must bematched to the applied inks, layers, and/or coatings of the inkset andonto the substrate. Additionally, the curing temperatures of any inks orlayers in the inkset must be considered in light of the melting ordegradation temperature of the bag itself. For example, bags formed ofcertain polymers cannot be subjected to heat levels sufficient to curecertain types of frequently used printed electronic inks.

In order to address certain of the foregoing of the concerns and yetobtain sufficient curing of the ink and additive process layers,different types of curing methodologies may be used in the embodiments.For example, convection curing using a convection box or conveyor beltmay be used to apply sufficient curing energy; likewise, infrared ornear infrared energy may be applied; additionally, ultraviolet curingmay be used; and photonic curing may also be employed. Yet further,ramping temperatures may be used in order to provide sufficient levelsof curing, such as wherein high or low temperatures are employed toimprove the ability of the print substrate to withstand more heat orenergy than might otherwise be the case.

FIGS. 3, 4, and 5 illustrate exemplary implementations of the disclosedembodiments. More particularly, FIG. 3 illustrates a conductor layer 12having contact points at the top right and bottom left of the heatingsystem. Further illustrated are discreet heater elements 18 a of theresistive layer 18, shown in the blow up of FIG. 3.

FIG. 4 illustrates an additional exemplary implementation of aconductive 12 and resistive layer 18 heating system. FIG. 5 illustratesan additional embodiment, in which the current choke point 502 of FIG. 4is remedied by enhancements in the size of the conductive layer 12associated with the contact pads at the top of the device. Of note, eachof the embodiments of FIGS. 3, 4, and 5 illustrate a dielectric layer 22printed over the conductive 12 and resistive layers 18, with the contactpoints extending beyond the dielectric layer 22 to allow for theinterconnections 54 discussed herein.

FIG. 6 illustrates an exemplary implementation of the heating system 10of FIG. 5 enclosed in an encapsulation layer 32. As noted throughout,the encapsulation layer 32 may protect the heating system 10 fromenvironmental conditions.

FIG. 7 illustrates an exemplary implementation in which the heatingsystem 10 has been laminated to a textile 702. Available textiles mayinclude, by way of non-limiting example, nylons, cottons, or the like.

FIG. 8 is a flow diagram illustrating an exemplary method 800 ofproviding a conformable heater. At step 802, an ink set is inter-matchedfor use to print compatible ink layers within the ink set, and ismatched to a receiving organic or inorganic conformable substrate. Atstep 804, a conductive layer formed of at least one ink from the ink setis printed on the substrate.

At step 806, a resistive layer is printed from the ink set, wherein theresistive layer provides at least a plurality of heating elements inelectrical communication with the conductive layer. At step 808, adielectric layer is printed from the ink set in order to insulate theconductive and resistive layers.

At optional step 810, the substrate having at least the conductive layerand the resistive layer printed thereon is at least partiallyencapsulated. At optional step 812, one or more sensors associated withthe operation of the heater may be integrated with and/or printed on thesubstrate.

At step 814, the heater is integrated with a wearable or a bag.Integrating may be by sewing, lamination, adhesion, or any likemethodology, including printing upon the bag. Moreover, at step 816, theheater may be connectively associated with one or more driver circuitshaving control systems communicative therewith, and with one or morepower source connections to allow for power to be supplied to theheating elements via the conductive layer. By way of example, step 816may include the printing or other manner of interconnecting of one ormore electrical interconnections to the heater.

FIG. 9 is a flow diagram illustrating a method 900 of using aconformable heater system. In the illustration, the conformable heatermay be associated with a power source at step 902. This association mayinclude a permanent association, such as via recharging of a permanentlyembedded battery, or a removable association, such as wherein anexternal power source, such as a battery, a mobile device, or the like,may be removably associated with the heater.

At step 904, the driver circuit that delivers power from the powersource to the heater may be variably controlled. Optionally, at step 904a, wireless control may be via a wireless connection, such as from amobile device to the driver circuit. This wireless, or a wired,connection may be controllable using a user interface provided by an“app” on the mobile device, by way of non-limiting example. The controlprovided thereby may be automated based on predetermined triggers oroperational limitations, manual, or a combination thereof. Wirelesscontrol may be provided over any known type of wireless interface.

Optionally, at step 904 b, wired control may be via a wired connectionfrom a mobile device to the driver circuit, such as via a micro-USBconnection to the heater. As will be understood by the skilled artisan,power may also be supplied via this connection in alternativeembodiments.

FIG. 10 illustrates an exemplary heater base, such as a fluid bag 1002,such as a medical fluid bag 1002, for fully containing one or morefluids within the bag between opposing plies 1004, 1006 of the bag. Thefluid contained within the bag may be, for example, blood or salinesolution. Of course, in embodiments, other fluids or gases may residewithin the “bag”, such as air in a wearables embodiment. The plies 1004,1006 may be sealed together to form a liquid (and/or gas) tight bag viaany methodology known in the art.

In the illustrated embodiment, one ply 1004 of the bag may have aprinted heater 1008 associated therewith, as discussed throughout, on anoutward facing aspect 1004 a of that first ply 1004 of the bag, and asensing circuit 1010 comprising a sensing chip 1012 printed on anoutward face 1006 a of the opposing ply 1006 of the fluid bag. In theillustrated embodiment, the IC chip 1012 may be a temperature sensor,the sensing circuit 1010 may be a temperature sensing circuit, and thesensing circuit 1010 may include one or more inputs and outputs 1020that may read data, write data, and/or connectively associate with powerand/or with at least one network, such as via wired or wirelessinterface.

In the illustrated embodiment, either or both of the heating circuit1008 and the sensing circuit 1010 may be printed circuits, and may beprinted directly onto the fluid bag 1002, or may be printed on aseparate substrate (not shown) that is then adhered to the fluid bag1002, such as by lamination or epoxy. Associated with the sensingcircuit side 1006 a of the fluid bag 1002 may be a printed antenna 1024,such as an RFID or NFC antenna, by way of non-limiting example, and theprinted sensing circuit 1010 may include one or more chip sets 1012, ormay include one or more inputs or outputs from or to one or more off-bagchip sets.

The sensor circuit 1010 provided may be a printed fluid level sensorcircuit, by way of non-limiting example. Alternatively, the sensorcircuit 1010 provided may be one or more printed or laminatedtemperature sensor circuits, by way of non-limiting example. Yetfurther, the printed sensor circuit 1010 provided may be a combinationtemperature sensor and level sensing circuit, which may or may not beassociated with one or more other sensing circuits for sensingadditional characteristics of fluid within the bag 1002.

The sensing circuit 1010 may be communicatively associated, such as viaone or more networks and network connections (such as using antenna1024), with one or more off-bag “apps” or applications, which mayprovide a human machine interface into data sensed by the printedsensing circuit 1010. This app or application may be provided, by way ofnonlimiting example, on one or more mobile devices, desktop or laptopcomputers, dedicated medical monitoring consoles, or the like. Data maybe provided from the sensing circuit to the one or more applications bya wire or wirelessly, such as using the printed RF or NFC antenna 1024discussed above.

FIGS. 11A, 11B, 11C and 11D illustrate a plurality of alternativeprinted heater data circuit designs 1008 a, 1008 b, 1008 c, 1008 d forphysical association with one ply 1006 of the fluid bag 1002. Moreparticularly, FIGS. 11A and 11B illustrate circuit designs 1008 a, 1008b for fixed resistance heaters, while FIGS. 11C and 11D illustrateexemplary circuit designs 1008 c, 1008 d for so-called “railroadpattern” heaters in which even heating and self-limiting temperature areprovided. As discussed throughout, the printed heater 1008 may bedirectly associated with a printed layer on the bag, such as a baseresistive layer, or may be printed on a substrate which is associatedwith a bag after printing of the heater. In either of saidcircumstances, various inks apparent to those skilled in the art may beemployed for use in the heater 1008 and/or in the sensor circuit 1010,such as Henkel PTC 120° C. carbon for the resistive layer, EMS CL-1036Silver for the conductive layer, and Henkel PF 455B Green for thedielectric layer, by way of nonlimiting example. Further and as will beunderstood, the printing processes performed in the embodiments maynecessarily include drying, pre-shrinking, and/or curing steps, such asUV curing steps, as will be apparent to the skilled artisan in light ofthe discussion herein.

FIG. 12 is an exemplary illustration of a sensor (and datalogging/sending circuit 1010 that may be printed on a ply 1006 of thebag that opposes the heating ply 1004. In the illustration of FIG. 12, athermocouple circuit 1202 may be printed directly onto the bag 1002and/or otherwise bonded to the bag 1002, such as using conductive epoxy,in order to partially provide a temperature sensing circuit 1010. Moreparticularly, carbon strips 1202 a, 1202 b, . . . may be screen printedonto the bag and conductively bonded to lead wires that lead off-bag andallow for reading of the temperature of fluid within the bag 1002. Ofnote, for the embodiment illustrated in FIG. 12 and other sensingembodiments discussed herein, each off-bag data “reading” system may beassociated with a single medical bag, or multiple fluid bags, whereinmultiple fluid bags may be read, and accordingly data receivedtherefrom, by a single “master” reading device which may then provideoutput data of the sensing to the human machine interface applicationdiscussed throughout.

In an alternative embodiment, FIGS. 13A and 13B illustrate printedcircuit layouts for sensor circuits 1010 e, 1010 f for association witha fluid bag 1002. In each illustration, silver ink may be used for, foeexample, two different conductive layers, and as shown designs forsensor circuits 1010 e, 1010 f may include two different dielectriclayers which may comprise two different printed inks. Also included inthe illustration are two alternative antennas 1024 a, 1024 b that allowfor the illustrated sensing circuits 1010 e, 1010 f to communicateoff-bag.

Significantly, as discussed throughout, and as illustrated withparticularity in FIGS. 13A and 13B, the sensor circuit 1010 e, 1010 fmay be printed to the bag 1002 layer by layer. Accordingly, the sensorcircuit 1010 of the embodiments comprises an ink set having particularcharacteristics, both in relation to the bag 1002 or print substrate,and in relation to the other inks within the ink set.

By way of nonlimiting example, these characteristics may include atleast the ability for any ink layer that must be associated with the bagto be comprised of an ink suitable to grip to the material of which thebag is constituted. Alternatively, the base layer/substrate of thesensing circuit print may be suitable to associate with an epoxy thatwill also permanently adhere to the outer surface of the bag ply.Additionally, each successive layer of ink must adhere in the propermanner to both the ink layer below and, in circumstances wherenecessary, the ink layer to be provided above that sequential layer.

Further, environmental factors must not adversely affect the performanceof each layer of the ink set. For example, bag “sweat”, i.e.,condensation, must not adversely affect any ink that will be printed oradhered in direct physical contact with the bag. Further, externalfactors must not affect the electrical interaction between layers tocause any undesired electrical interference or interaction. Of course,one or more protection layers may be printed over or below the circuitor any layer of the circuit, but, in the same manner as is discussedabove, such protective layers must comport with each layer of the inkset placed below and above, and must not cause unwanted interactions orcircuit decay. In particular embodiments, ink sets may include any of avariety of dielectric inks, such as those discussed throughout, andconductive ink layers, such as the copper and silver inks discussedthroughout.

In the illustration of FIG. 13, print widths may be carefully monitoredand controlled, such as will be apparent to the skilled artisan in lightof the discussion herein. For example, conductive, i.e., silver, tracewidths may vary in accordance with Table 1, provided immediately below:

TABLE 1 Screen Design Actual Width Printed width Percent Area (μm) (μm)(μm) spread Antenna 635 616.63 ± 4 646.26 ± 5 4.8% Large 500 485.26 ± 9508.97 ± 7 4.9% Small 250 239.44 ± 5 266.30 ± 6 2.9%

FIGS. 14A, 14B, and 14C illustrate, by way of nonlimiting example, ahuman machine interface app/application 1402 as discussed throughout. Inthe application illustrated in FIG. 14, the application is associatedwith a mobile device 1404, such as a smart phone. As shown, the sensingcircuit in the illustrated embodiment is a temperature sensing circuit,and a user may have a variety of options available to start, stop,clear, or reset the temperature sensing in association with one or morefluid bags. Other options may additionally be available to the user,such as changes in temperature measurement, a history of measurementsover a given time period, such as may be a searchable time period, andthe like. Further, and as illustrated with particularity in FIGS. 14Band 14C, temperature data may be provided in numeric format, orgraphically, by way of nonlimiting example, and over one or morepredetermined or selected time frames.

As will be appreciated by the skilled artisan, rather than associateparticular filtering with the printed sensing circuit or firmwarediscussed herein, adjustment algorithms may be included in theapplication illustrated in FIG. 14, or in similar off-bag, remote,and/or human machine interface applications. For example, adjustmentalgorithms may account for the thickness or makeup of particular brandsof fluid bags, particular heating circuits that may be associated withthe fluid bag, or the like, by way of nonlimiting example.

As discussed throughout, and as illustrated in FIGS. 15 and 16, one ormore additional protective layers 1502 may be provided over the sensingcircuit 1010. Such protective outermost layers may be similar to thosediscussed above with respect to protecting a heating circuit printed onthe other ply of the bag. Such a protective layer 1502 may be formed ofa dielectric, by way of nonlimiting example, and may thereby preventoxidation of the conductive layers 1504 of the sensing circuit, mayprotect the circuit, traces, and electrical connections from physicaldamage, and may reinforce the proper conductive nature of the traces,particularly at the edges of encapsulated areas.

More particularly, specific and/or more extensive protective printedlayers may be provided in association with particularly delicateportions of the printed sensing circuit, and/or in association withparticularly complex applications for circuit 1010. By way of example,because of variations in bag curvature when an intravenous (IV) bag isfilled versus empty, a more rigid secondary under layer or cover layer1702 may be provided in association with the printed antenna 1024 of thesensing circuit 1010. This may keep the antenna 1024 as flat aspossible, thereby maximizing communication integrity and read range forthe printed sensing circuit 1010. Such embodiments are illustrated, byway of nonlimiting example, in FIGS. 17A, 17B and 17C.

In addition to the temperature sensing circuit discussed throughout,also referenced above is a fluid level sensing circuit. Such a circuitmay monitor fluid levels within the bag and may thereby allow forautomated indications of the need for bag replacement and the like. Suchsensing, although not illustrated with particularity herein, may haveaccess thereto also provided through the human machine interfaceapplication discussed throughout.

A fluid level sensing circuit may comprise, by way of example, aself-capacitive sensing circuit, such as may include a plurality ofsilver traces used to measure bag capacitance at various locationsacross the bag. Additionally and alternatively, rather than capacitivestrips, capacitor buttons may be placed along particular areas of a plyof the fluid bag. Each button may act as a capacitive detector toindicate whether the fluid has reached that level. Of course, othermethods of printing level sensing circuits, such as capacitive levelsensors, will be apparent to those skilled in the art in light of thediscussion herein and may be subjected to the ink set limitationsdiscussed throughout.

By way of nonlimiting example, a sensing circuit 1010 may include one ormore conductive inks, such as EMS CL-1036 Silver ink, and one or moredielectric layer inks, such as EMS DL-7540 Blue. Conductive adhesivesfor certain of the layers may be comprised of any conductive adhesiveknown to those skilled in the art for incorporation into the instantembodiments, such as Henkel QML516LE, Henkel 2030 SC, and HenkelSL-5421. The encapsulating layer may be comprised of any known principlematerial, such as laminate VE 529610.

Further, the descriptions of the disclosure are provided to enable anyperson skilled in the art to make or use the disclosed embodiments.Various modifications to the disclosure will be readily apparent tothose skilled in the art, and the generic principles defined herein maybe applied to other variations without departing from the spirit orscope of the disclosure. Thus, the disclosure is not intended to belimited to the examples and designs described herein, but rather is tobe accorded the widest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A flexible heater sensor suitable for associationwith a fluid bag, comprising: a conformable substrate on a ply of thefluid bag opposite a printed flexible heater; a matched function inkset, printed onto at least one substantially planar face of thesubstrate to form: at least one conductive layer capable of receivingcurrent flow from at least one power source; and at least one dielectriclayer capable of at least partially insulating and at least partiallylimiting conductivity of the at least one conductive layer; wherein thematched ink set is matched to preclude detrimental interactions betweenthe printed inks of each of the at least one conductive and dielectriclayers, and to preclude detrimental interactions with the conformablesubstrate; and wherein the at least one conductive layer and the atleast one dielectric layer comprise a sensing circuit that senses atleast the temperature of fluid within the fluid bag.
 2. The flexibleheater sensor of claim 1, wherein the substrate comprises an inorganicsubstrate
 3. The flexible heater sensor of claim 1, wherein thesubstrate comprises one selected from the group consisting of PET, PC,TPU, nylon, glass, fabric, PEN, and ceramic.
 4. The flexible heatersensor of claim 1, wherein the detrimental interactions occur during atleast one of deposition and curing of the printed inks.
 5. The flexibleheater sensor of claim 1, wherein the printed inks in the matched inkset include ones selected from the group consisting of silver, carbon,PEDOT:PSS, and CNT inks.
 6. The flexible heater sensor of claim 1,wherein the printed ink set withstands environmental factors includingat least moisture.
 7. The flexible heater sensor of claim 1, furthercomprising an encapsulation that at least partially seals at least theconformable substrate having the matched function ink set thereon fromenvironmental factors.
 8. The flexible heater sensor of claim 7, whereinthe encapsulation comprises a lamination.
 9. The flexible heater sensorof claim 1, wherein the sensing circuit also senses the fluid level ofthe fluid in the fluid bag.
 10. The flexible heater sensor of 9, whereinthe fluid level sensing comprises a plurality of capacitive strips. 11.The flexible heater sensor of claim 1, wherein the conformable substratecomprises the ply.
 12. The flexible heater sensor of claim 1, whereinthe conformable substrate is adhered to the ply.
 13. The flexible heatersensor of claim 1, wherein the sensing circuit comprises a wirelesssender.
 14. The flexible heater sensor of claim 13, wherein the wirelesssender comprises at least one of a Bluetooth, WiFi, NFC, cellular and RFsender.
 15. The flexible heater sensor of claim 13, wherein the wirelesssender interacts data from the sensing circuit to a remote mobile deviceapp.
 16. The flexible heater sensor of claim 15, wherein the mobiledevice app comprises a plurality of adjustment algorithms for the data,including for a type of the fluid bag.
 17. The flexible heater sensor ofclaim 1, wherein the power source comprises a rechargeable battery. 18.The flexible heater sensor of claim 1, wherein the dielectric layerinsulates aspects of the conductive layers from shorting onto oneanother due to the conformability of the conformable substrate.
 19. Theflexible heater sensor of claim 1, wherein ones of the dielectric layerscomprise reinforcement layers.
 20. The flexible heater sensor of claim1, wherein the fluid bag is an IV bag.